Check valve with hanger

ABSTRACT

A large diameter check valve has an upstream inlet part mountable on a discharge end of a conduit, a downstream outlet part adapted to prevent backflow of fluid through the check valve, and a transition part located between the upstream inlet part and the downstream outlet part. A support is included in the check valve to prevent drooping of the check valve via a cantilever effect. A method for supporting a check valve is also disclosed.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates generally to check valves and, inparticular, to duckbill check valves with support assemblies.

[0003] 2. Description of Related Art

[0004] A check valve is essentially a valve which allows fluid to flowin only one direction through a conduit, while closing and preventingback or reverse flow, when back pressure builds up downstream of thevalve to a level greater than the upstream fluid pressure head. Checkvalves are used in various fluid transportation operations and mustinclude some means of allowing a forward flow of liquid yet preventingany backflow.

[0005] Conventional elastomeric duckbill check valves have an inlet cuff(or a flange), an outlet bill and a transitional middle part forconnecting the cuff and the bill. The bill includes a slit, which openswhen fluid is forced through the valve. Typically, existing duckbillcheck valves have a bill slit length dimension that is equal to or lessthan one-half the inlet cuff's circumference.

[0006] To improve the performance of duckbill check valves, valves havebeen recently developed in which the width of the bill is larger thanthe diameter of the cuff. The area of the outlet part in the openposition, thus approaches the area of the inlet part, and the headlossdecreases. For example, U.S. Pat. No. 5,931,197 to Raftis et al.discloses an asymmetrical valve of this type and U.S. Pat. No. 6,367,505to Raftis et al. discloses a check valve with an oversized bill.

[0007] Additionally, duckbill check valves have been recently mounted tothe end of a pipe with the bill in the vertical position. By having thebill in the vertical position, the pipe will drain completely. Moreover,with bills in the vertical position, the stiffness of the duckbill checkvalve is increased. However, even with bills being placed in a verticalorientation, large diameter elastomeric duckbill check valves that are36 inches in diameter or larger have a tendency to “droop” or sag undertheir own weight. The weight of the output area distorts the sealingarea and allows backflow of water or sewage, which the valve is supposedto prevent.

[0008] As is broadly discussed in U.S. Pat. No. 6,367,505 to Raftis etal., local reinforcements may be embedded in the elastomeric material ofa check valve with an oversized bill to enhance the stiffness of theelastomeric portion of the valve. Furthermore, as illustrated in U.S.Pat. No. 4,607,663 to Raftis et al., staggered embedded pads are used toprovide sufficient strength for inversion and sagging resistance in atide gate valve application. Moreover, EP 1077339A2 to Raftis and Duerteaches use of a support body receivable in the tide gate valve cavitybut this is directed to reinforcing the transition part, so as to helpprevent the tide gate valve from collapsing in and on itself whensubject to backflow.

[0009] It is therefore an object of the present invention to provide acheck valve assembly that overcomes the design problems associated withprior art duckbill check valves and to address the problem of droopingin large check valves. It is another object of the present invention toprovide an improved duckbill check valve, which reduces the amount ofunwanted backflow by decreasing the tendency of larger check valves to“droop” or “sag” under their own weight. It is further the object of thepresent invention to provide a support mechanism that can either beembedded or connected to an inner or outer portion of elastomericmaterial at only one location in the valve.

SUMMARY OF THE INVENTION

[0010] Disclosed is a duckbill check valve for preventing the backflowof fluid. The check valve is comprised of an inlet part mountable on thedischarge end of a conduit, a downstream outlet part adapted to preventbackflow of fluid through the check valve a transition part locatedbetween the inlet part and the outlet part, and a support connected toan upper portion of the inlet part and at least the transition part.

[0011] The support can be embedded within the check valve, or attachedto the inner surface or outer surface of the check valve by appropriatemeans. The support can consist of a rigid, curved plate, which caninclude ribs to increase the strength of the plate. Alternatively, thesupport can consist of a section of short curved plate being attached tothe inlet part, with a bar extending from the short curved plate to atleast the transition part. Additionally, the support can be adapted tobe used in with a duckbill check valve having a “flanged” type mount.

[0012] A method is disclosed for supporting a duckbill check valve. Themethod is comprised of providing a support that can be attached to theinlet part and at least the transition part of the check valve such thatthe support forms a cantilever that extends from the end of the conduitinto the check valve. The check valve thus hangs from the support. Thesupport is attached to either the inside surface or the outer surface ofthe check valve.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1a is a side view of the first embodiment of the presentinvention in a closed position;

[0014]FIG. 1b is a top view of the first embodiment of the presentinvention in a closed position;

[0015]FIG. 1c is a top view of the support of FIGS. 1a and 1 b accordingto the first embodiment of the present invention;

[0016]FIG. 1d is an end view of the support of FIGS. 1a and 1 baccording to the first embodiment of the present invention;

[0017]FIG. 2a is a side view of the second embodiment of the presentinvention in a closed position;

[0018]FIG. 2b is a top view of the second embodiment of the presentinvention in a closed position;

[0019]FIG. 2c is a top view of the support of FIGS. 2a and 2 b accordingto the second embodiment of the present invention;

[0020]FIG. 2d is an end view of the support of FIGS. 2a and 2 baccording to the second embodiment of the present invention;

[0021]FIG. 3a is a side view of the third embodiment of the presentinvention in a closed position;

[0022]FIG. 3b is a top view of the third embodiment of the presentinvention in a closed position;

[0023]FIG. 3c is a top view of the support of FIGS. 3a and 3 b accordingto the third embodiment of the present invention;

[0024]FIG. 3d is an end view of the support of FIGS. 3a and 3 baccording to the third embodiment of the present invention;

[0025]FIG. 4a is a side view of the fourth embodiment of the presentinvention in a closed position;

[0026]FIG. 4b is a top view of the fourth embodiment of the presentinvention in a closed position;

[0027]FIG. 4c is a top view of the support of FIGS. 4a and 4 b accordingto the fourth embodiment of the present invention;

[0028]FIG. 4d is an end view of the support of FIGS. 4a and 4 baccording to the fourth embodiment of the present invention;

[0029]FIG. 5a is a top view of the support according to the fifthembodiment of the present invention;

[0030]FIG. 5b is an end view of the support according to the fifthembodiment of the present invention.

[0031]FIG. 6a is a top view of the support according to the sixthembodiment of the present invention;

[0032]FIG. 6b is an end view of the support according to the sixthembodiment of the present invention;

[0033]FIG. 7a is a top view of the support according to the seventhembodiment of the present invention;

[0034]FIG. 7b is an end view of the support according to the seventhembodiment of the present invention;

[0035]FIG. 8a is a top view of the support according to the eighthembodiment of the present invention; and

[0036]FIG. 8b is an end view of the support according to the eighthembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] The duckbill check valve assembly of the present invention isuseful in many specialized applications, but particularly for use indrainage and sewage water effluent outfall lines.

[0038] A duckbill check valve 10 with a support 20 according to thefirst embodiment of the present invention is shown in FIGS. 1a and 1 b.The duckbill check valve 10 is comprised of an inlet part 16, atransitional part 18 and an outlet part 24, which appears as a pair of“lips” facing and engaging one another. The support 20 is comprised of aplate 22 attached or embedded to the duckbill check valve 10. The dashedlines indicate the outer periphery of the plate 22, when installed. Theprofile of the plate 22 basically mirrors the internal surface of thecheck valve in the inlet and transition (or “saddle”) regions.

[0039] The duckbill check valve 10 is preferably made from an elastomer,such as neoprene, or an elastomer reinforced with synthetic fiber, suchas nylon or polyester, with construction similar to an automobile tire.The inlet part 16 is generally made of a stiff, durable material, suchas styrene butadiene, with polyester fabric reinforcing, whereas theoutlet part 24 is made of a flexible material to allow proper openingand closing of the outlet part 24. The inlet part 16 is connected to theend of the customer's pipe 12 by a mounting mechanism 14, a “slip-on”type that consists of using steel band or clamps 26. The support 20,such as the plate 22, which is attached to the elastomeric portion ofthe duckbill check valve 10, is preferably made of metal or othersuitable material. The plate 22 has one portion secured to the inletpart 16, and another portion extending into at least the transition part18 of the valve 10. The plate 22 essentially forms a cantileverextending from the pipe 12 into the duckbill check valve 10, and thussupports the valve which, in a sense, “hangs” from the plate.

[0040] This support 20 can be integral (or “embedded”) with the duckbillcheck valve 10, which means that it is built in while the duckbill checkvalve 10 is being fabricated. Alternatively, the support 20 may beinstalled, either inside or outside of the duckbill check valve 10 afterthe duckbill check valve 10 is manufactured. Presently, the plate 22 canbe fastened to the duckbill check valve 10 by using mounting mechanism14 to secure the plate 22 to the inlet part 16 and by using acceptablefasteners, which include adhesives, screws, bolts and nuts, rivets, orwire, to attach the plate 22 to at least the transition part 18.Preferably, the plate 22 is inserted during the building process of theduckbill check valve 10 and vulcanized into place. This has theadvantage of protecting support 20, when made of steel or other suchmaterials, from the corrosive effects of the process fluids. It alsoprovides a strong bond between the support 20 and the duckbill checkvalve 10. Moreover, to increase the bond strength between the support20, such as a plate 22, and the elastomeric portion of the duckbillcheck valve 10, a plurality of holes 28 may be drilled or punched in theplate 22, as is illustrated in FIGS. 1c and 1 d.

[0041] It is important to note that the outlet part 24 may be orientedin different positions, rotatable about the axis of the customer's pipe12. FIG. 1a shows the outlet part 24 of the present invention whereinthe outlet part 24 or “lips” is oriented in a vertical manner. Largediameter duckbill check valves 10 (i.e., twenty (20) inches in diameteror greater) are typically mounted to the end of a customer's pipe 12with the outlet part 24 in a vertical position. By having the verticalorientation of the outlet part 24, the duckbill check valve 10 willdrain completely. If the outlet part 24 were in a horizontal position,it would be on the horizontal centerline of both the duckbill checkvalve 10 and the customer's pipe 12. Therefore, the customer's pipe 12would not drain below this centerline.

[0042] Furthermore, by having the outlet part 24 in a vertical position,the stiffness of the duckbill check valve 10 is increased, but even so,large duckbill check valves tend to “droop.” This “drooping” effectallows the sealing area of the outlet part 24 to become distorted, whichsubsequently opens up and allows a backflow of water or sewage, whichthe duckbill check valve is supposed to prevent. The support 20, such asthe plate 22, decreases the tendency of outlet part 24 to “droop” underits own weight.

[0043] A duckbill check valve 10 with a support 20 according to a secondembodiment of the present invention is shown in FIGS. 2a and 2 b. Inthis embodiment, the duckbill check valve 10 is similar to the firstembodiment duckbill check valve 10, with like reference numeralsindicating similar parts. The second embodiment duckbill check valvealso includes at least one bar or “rib” 30 to strengthen the plate 22,as is illustrated in FIGS. 2c and 2 d. This bar 30 allows the plate 22to be thinner and lighter while maintaining the necessary strength tosupport the duckbill check valve 10. This “rib” can be attached to theplate by appropriate means, such as welding, or alternatively, can beintegrally formed into the support plate. Although two bars 30 areillustrated in FIGS. 2a and 2 b, the number of bars 30 can be only oneor can be as many as will fit on the plate 22. The bars 30 can belocated on the top, bottom or on both sides of the plate 22 as long asthere is enough space to support the number of bars desired.

[0044] A duckbill check valve 10 with a support 20 according to a thirdembodiment of the present invention is shown in FIGS. 3a and 3 b. Inthis embodiment, a duckbill check valve 10 is similar to the firstembodiment duckbill check valve 10, with like reference numeralsindicating similar parts. The third embodiment duckbill check valveillustrates that a support 20 such as a plate 22 can be used inconjunction with a duckbill check valve 10 assembly that uses a“flanged” type mount 32. Here, mounting mechanism 14 consists primarilyof customary pipe flange techniques, including nuts and bolts to securethe two meeting flanges on the pipe end and on the valve, respectively.Additionally, to increase the bond strength between the plate 22 and theelastomeric portion of the flange 32 in duckbill check valve 10, aplurality of holes 28 are drilled or punched in the plate 22, asillustrated in FIGS. 3c and 3 d.

[0045] It is important to note that a support 20 similar to the firstembodiment of the present invention can be used with many of thecurrently available check valves that use a “flanged” type mount 32.However by using a support 20 according to the third embodiment of thepresent invention in conjunction with a “flanged” type mount 32, thestrength of the support can be increased.

[0046] A duckbill check valve 10 with a support 20 according to a fourthembodiment of the present invention is shown in FIGS. 4a and 4 b. Inthis embodiment, the duckbill check valve 10 is similar to the secondembodiment duckbill check valve 10, with like reference numeralsindicating similar parts. The fourth embodiment duckbill check valveillustrates that a support 20 such as a plate 22 can be used inconjunction with a duckbill check valve 10 assembly that uses a mountingmechanism 14 that is considered to be a “flanged” type 32. Moreover, thefourth embodiment duckbill check valve 10 also includes bars or “ribs”30 to strengthen the support plate 22, as illustrated in FIGS. 4c and 4d.

[0047] A support 20 according to a fifth embodiment of the presentinvention is shown in FIGS. 5a and 5 b. In this embodiment, the support20 is disposed within or on a duckbill check valve similar to both thefirst and second embodiments of duckbill check valves 10. The support 20for the duckbill check valve 10 consists of at least on bar 34 welded toa short curved plate 23 for holding the assembly in place. The shortcurved plate 23 would be in the inlet part 16 and the bar 34 in at leastthe transition part 18.

[0048] Preferably, the fifth embodiment has both the short curved plate23 and bar 34 inserted during the building process of the duckbill checkvalve 10 and vulcanized into place. This has the advantage of protectingthe support 20, when made from steel or other similar materials, fromthe corrosive effects of the process fluids. It also provides a strongbond between the support 20 and the duckbill check valve 10.Alternatively, the short curved plate 23 and the bar 34 can beinstalled, either inside or outside of the duckbill check valve 10,using a suitable fastening means 14 such as adhesives, screws, bolts,and nuts, or wire after the check valve is manufactured.

[0049] A support system 20 according to a sixth embodiment of thepresent invention is shown in FIGS. 6a and 6 b. In this embodiment, thesupport 20 is disposed within or on a duckbill check valve similar tothe fifth embodiment duckbill check valve 10. The sixth embodimentduckbill check valve illustrates that a support 20, including at leastone bar 34 welded to a short curved plate 23, can be used with duckbillcheck valves 10 that use a mounting mechanism 14 that is considered tobe a “flanged” type 32. The plate 22 would be received in the flange 32,and the bar 34 in the saddle 18.

[0050] A support 20 according to a seventh embodiment of the presentinvention is shown in FIGS. 7a and 7 b. In this embodiment, the supportis disposed with or on a duckbill check valve similar to the fifthembodiment duckbill check valve 10. The seventh embodiment duckbillcheck valve 10 utilizes two bars 34 instead of one bar 34 as illustratedin FIG. 5. The only limitation on the number of bars 34 that can be usedis the physical space available to fit them in. Again, short curvedplate 23 (with holes 28) is received in the inlet part 16, with bars 34received in at least the transition part 18.

[0051] Similarly, a support 20 according to an eighth embodiment of thepresent invention is shown in FIGS. 8a and 8 b. In this embodiment, thesupport 20 is disposed within or on a duckbill check valve similar tothe sixth embodiment duckbill check valve 10. The eighth embodimentduckbill check valve 10 utilizes two bars 34 instead of one bar 34 asillustrated in FIG. 6. The only limitation on the number of bars 34 tobe used is the physical space available to fit them in.

[0052] A method for supporting a duckbill check valve includes the stepof installing the support of any of the previously disclosed embodimentsof the present invention on either the inside or outside surface of thecheck valve. Preferably, the support is installed while the check valveis mounted on the customer's pipe, but may be done elsewhere.

[0053] This invention has been described with reference to the preferredembodiments. Obvious modifications and alterations will occur to othersupon reading and understanding the preceding detailed description. It isintended that the invention be construed as including all suchmodifications and alterations.

The invention claimed is:
 1. A large diameter check valve, comprising:an upstream inlet part mountable on the discharge end of a conduit; adownstream outlet part adapted to prevent backflow of fluid through thecheck valve; a transition part located between the upstream inlet partand the downstream outlet part; and a rigid support connected to anupper portion only of at least said inlet part and said transition part.2. The check valve of claim 1, where said support is embedded withinsaid check valve.
 3. The check valve of claim 1, where said supportincludes a plate.
 4. The check valve of claim 1, where said support isattached to the outer surface of said check valve.
 5. The check valve ofclaim 1, where said support is attached to the inner surface of saidcheck valve.
 6. The check valve of claim 1, where said outlet part ismounted with a vertical orientation.
 7. The check valve of claim 1,further comprising a flange on the upstream inlet part.
 8. The checkvalve of claim 1, where said check valve is made at least in part froman elastomeric material.
 9. The check valve of claim 8, furthercomprising a synthetic fiber reinforcement in said elastomeric material.10. The check valve of claim 1, where said upstream inlet part is madeat least in part from a stiff durable material.
 11. The check valve ofclaim 1, where said upstream inlet part includes a polyester fabricreinforcement.
 12. The check valve of claim 2, where said support plateincludes a plurality of holes.
 13. The check valve of claim 1 where saidsupport comprises a plate having at least one reinforcing rib thereon.14. The check valve of claim 3 further comprising a first flange on saidupstream inlet part, and where said support further comprises a secondflange being connected to said plate, said first flange being connectedto said second flange.
 15. The check valve of claim 1, where saidsupport is comprised of a curved plate connected to said inlet part andat least one bar being attached to said curved plate and at least tosaid transition part.
 16. The check valve of claim 15, furthercomprising a first flange on said upstream inlet part, and where saidsupport further comprises a second flange connected to said curvedplate, said first flange being connected to said second flange.
 17. Asupport mountable on a check valve having an inlet part, an outlet partand a transition part, the support comprising: a plate having a size andcontour similar to an upper portion of at least the inlet part and thetransition part of the check valve; and means for securing the plate tothe upper portion of the check valve.
 18. The support of claim 17, wheresaid plate includes at least one rib.
 19. The support of claim 17,further comprising a flange connected to said plate, said flange beingsuitable for connecting to an upper portion of a duckbill check valvethat includes a flange.
 20. The support of claim 17 wherein the plateincludes holes to assist in securing the plate to the check valve.
 21. Asupport mountable on a duckbill check valve, comprising a short curvedplate capable of being connected to the inlet part of the duckbill checkvalve, and at least one bar connected to the curved plate and capable ofbeing connected to at least the transition part of the check valve. 22.The support of claim 21, further comprising a flange connected to saidshort curved plate, said flange being suitable for connecting to anupper portion of a duckbill check valve that includes a flange.
 23. Amethod for supporting a large diameter check valve consisting of aninlet part, a transition part, and an outlet part including the stepsof: providing a rigid, curved plate whose contour and size matches anupper portion of at least the inlet part of the check valve; securingthe curved plate to the upper portion of the check valve; and supportingat least the inlet part and transition part of the check valve with acantilever effect via the curved plate.
 24. The method of claim 23,where said plate is installed on the outer surface of the check valveand the plate is further secured to an end of a conduit.
 25. The methodof claim 23, where said plate is installed on the inner surface of thecheck valve and the plate is further secured to an end of a conduit. 26.The method of claim 23 wherein the plate is embedded within the checkvalve.
 27. The method of claim 23 including the step of attaching a barto the curved plate and further attaching the bar to the transition partto facilitate the cantilever effect.